Synthesis of sulfamoylbenzamide derivatives as HBV capsid assembly effector

Abstract

The synthesis of novel series of sulfamoylbenzamides as HBV capsid assembly effector is reported. The structure was divided into five parts which were independently modified as part of our lead optimization. All synthesized compounds were evaluated for their anti-HBV activity and toxicity in human hepatocytes, lymphocytes and other cells. Additionally, we assessed their effect on HBV cccDNA formation in an HBeAg reporter cell-based assay. Among the 27 compounds reported, several analogs exhibited submicromolar activities and significant reduction of HBeAg secretion. Selected compounds were studied under negative-stain electron microscopy for their ability to disrupt the HBV capsid formation. Structures were modeled into a binding site recently identified in the HBV capsid protein for similar molecules to rationalize the structure-activity relationships for this family of compounds.

Novel Hepatitis B Virus Capsid Assembly Modulator Induces Potent Antiviral Responses In Vitro and in Humanized Mice

“…Structurally these compounds are heteroaryldihydro-pyrimidines (HAPs), phenylpropenamides (PP), or sulfamoylbenzamides (SBA). Here, we report the discovery and the preclinical characterization of GLP-26, a novel CAM with a unique glyoxamidopyrrolo backbone, obtained through chemical optimization of early SBA derivatives identified by our team (19).…”

Mechanism of action of HBV capsid assembly modulators predicted from binding to early assembly intermediates

“…HBV Cp149 protein was expressed in BL21 E.coli and isolated using established chromatographic methods 11 . Capsid particle formation was induced by decreasing pH and addition of NaCl overnight.…”

“…It is characterized by a persistent presence of covalently closed circular DNA (cccDNA) in the infected hepatocytes, which is not eliminated by presently approved therapies [2][3][4] . A promising orthogonal approach for eliminating the infection is to target HBV nucleocapsid [5][6][7][8][9][10][11][12][13] . Capsid assembly modulators (CAMs) are small molecules that affect capsid assembly by interacting with the capsid proteins 5-10, 12, 13 .…”

“…Capsid assembly modulators (CAMs) are small molecules that affect capsid assembly by interacting with the capsid proteins 5-10, 12, 13 . Different assembly effects, such as acceleration or misdirection, have been achieved by different CAMs [5][6][7][8][9][10][11][12][13] . It was also discovered that CAMs can both inhibit virus replication and interfere with cccDNA synthesis, suggesting that they could help eliminate the virus from hepatocytes more efficiently 5,6 .…”

“…mechanistic classes (see Figure S1 for structures). Heteroaryldihydropyrimidines (HAPs) misdirect the capsid assembly into non-capsid structures 5,6 , while phenylpropenamides (PPAs) 7,8 and sulfamoyl benzamides (SBAs) [9][10][11] induce formations of capsids lacking the viral DNA. Although both PPAs and SBAs cause formation of empty capsids, it has been shown that some PPAs, e.g, AT130, also increase the assembly rate of Cp149 8 .…”